DFRobot has a very cool network controlled RLY-8 relay module that is easily manageable by a TCP connection or serial over USB. Using TCP is more powerful because there ie a possibility to use simple JSON formatted commands.
In case if you just want to enable some relays it is enough to use telnet and send that JSON commands but in the era of smart homes we want more.
So I made this java SpringBoot web app that brings a wery simple webpage where you can switch that relays remotely. It also has login page so you can publish this app into the internet and you can control your home stuff from everywhere.
There is a possibility to edit the labels of the relays within this property file
It is also you can configure some important values within this application.yml file. It is wery important to change the login password and of course your relay ip address.
To bring up the application you need to proceed the following steps.
First of all you need to have Java 8 and Gradle installed.
Tha application is using Gradle, so to build you just run gradle clean build
After the successful build the application jar will be build/libs/relay8-0.1.0-SNAPSHOT.jar
To run the application firs copy the jar fle in their final destination go into that folder and run
java -jar relay8-0.1.0-SNAPSHOT.jar
In your browser go tho the address http://localhost:7777 and you will find this login screen:
Use your login credentials that you are set in the file application.yml and you are done.
This page will be loaded:
When this page is opening the state of the relays will be fetched from the device and the switches will set properly. There is also the device name is fetched and used as title. Of course the screenshot has modified labels (label.properties).
At that moment when you switch a relay that is immediately will set also at the device. In case of any failure an error message will shown and all the switches wil be hidden.
If you are lazy enough to modify the settings in application.yml file you can start the application in that way to override some default settings. An example if you want to start the application with a specific device IP address and a custom password, just run:
java -Drly8.host=192.168.1.10 -Dspring.security.user.password=your_password -jar relay8-0.1.0-SNAPSHOT.jar
You can deploy the application also to a RaspberryPI (but be sure you have Java 8 on it) and use different public and free services to have access into your application without port forwarding.
The most of the features encountered at the chapters below are using properties from a dedicated YAML file. This file can be changed at runtime and any modification will be updated properly. This dynamic file name is triggers.yml and that needs to be placed in the working directory. An example file is looking like this:
sensors:
irrigation:
type: yaml
source: /var/app/environment/environment.yml
key: outside.irrigation
triggers:
backyard:
relay: 1
cron: "0 */1 * * * ?"
sensor: irrigation
goose_lake:
relay: 1
cron: "0 0 6,18 * * ?"
switchback:
relay1: 40
relay2: 0
relay3: 0
relay4: 0
relay5: 0
relay6: 0
relay7: 0
relay8: 0
The following chapters will detail each of those sections.
You can fully automate your relays switch on by specifying a cron per relay. First you need to switch on this funtionality by setting the rly8.relay?.auto property (true) in the application.yml. As a second step you can specify a cron string for the rly8.relay?.cron property.
In case if you want to automatically switching off a relay after a predefined time please set the rly8.relay?.switchback property in the application.yml. The value is in minutes and 0 means no switchback.
The application can be used also in test mode, without the RLY-8 device. For this please start tha applciation with the parameter -Ddummy.device=true